Premium
ACGT‐containing abscisic acid response element (ABRE) and coupling element 3 (CE3) are functionally equivalent
Author(s) -
Hobo Tokunori,
Asada Mihoko,
Kowyama Yasuo,
Hattori Tsukaho
Publication year - 1999
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.1999.00565.x
Subject(s) - abscisic acid , promoter , linker , chemistry , stereochemistry , response element , gene , regulatory sequence , biology , biochemistry , transcription factor , gene expression , computer science , operating system
Summary ACGT‐containing ABA response elements (ABREs) have been functionally identified in the promoters of various genes. In addition, single copies of ABRE have been found to require a cis ‐acting, coupling element to achieve ABA induction. A coupling element 3 (CE3) sequence, originally identified as such in the barley HVA1 promoter, is found approximately 30 bp downstream of motif A (ACGT‐containing ABRE) in the promoter of the Osem gene. The relationship between these two elements was further defined by linker‐scan analyses of a 55 bp fragment of the Osem promoter, which is sufficient for ABA‐responsiveness and VP1 activation. The analyses revealed that both motif A and CE3 sequence were required not only for ABA‐responsiveness but also for VP1 activation. Since the sequences of motif A and CE3 were found to be similar, motif‐exchange experiments were carried out. The experiments demonstrated that motif A and CE3 were interchangeable by each other with respect to both ABA and VP1 regulation. In addition, both sequences were shown to be recognized by a VP1‐interacting, ABA‐responsive bZIP factor TRAB1. These results indicate that ACGT‐containing ABREs and CE3 are functionally equivalent cis ‐acting elements. Furthermore, TRAB1 was shown to bind two other non‐ACGT ABREs. Based on these results, all these ABREs including CE3 are proposed to be categorized into a single class of cis ‐acting elements.